Denmark, Aarhus. A new research project aims to reduce methane emissions from dairy cows by up to 25%. In a new research project, researchers from Aarhus University in cooperation with Organic Denmark and a number of commercial partners will be examining whether the addition of organic oregano to cattle feed can reduce the production of methane in the rumen and thus emissions of methane gas.
Methane emissions from cows are a large problem for the climate. When ruminants digest their feed, methane is formed as a natural by-product of the microbial process in the rumen, and since methane is a 25 times more powerful greenhouse gas than carbon dioxide, there is a need to devise methods to reduce such emissions from cattle.
Methane production can be reduced by, for example, adding fat or nitrate to the feed or by increasing the starch content and improve the feed quality. But for organic dairy farmers, these remedies are either not permissible or are already being used.
“Oregano – especially the species Greek oregano (Origanum vulgare ssp hirtum) – is known for its high content of essential oils and its antimicrobial effect, and the plant is a natural tool for reducing methane production in the rumen”, says project manager and Senior Researcher at the Department of Food Science, Kai Grevsen, and continues: “The goal is to show that we can reduce methane emissions from dairy cows by up to 25% by adding oregano to the feed.”
As part of the project, researchers will initially test the effect of supplementing with oregano on rumen- and intestinal-fistulated dairy cows in special methane chambers. They will also examine how the cows react to different amounts of oregano. The feeding with oregano will then be tested in practice on a number of organic dairy farms producing milk for ‘Naturmælk’ (organic dairy). The four-year project will also investigate how best to grow organic oregano and whether to process the plant either as hay or silage.